DENSE CALCIFICATION IN A CASE OF GIANT GROWTH HORMONE-SECRETING PITUITARY ADENOMA

Abstract

INTRODUCTION
Calcification is an uncommon feature of pituitary adenomas and extensive calcification evident radiologically is especially rare and is technically challenging for surgical removal. We report a case of a giant growth hormone (GH)-secreting pituitary adenoma with dense tumoral calcification which is an uncommon presentation.

CASE
A 31-year-old male first presented to the surgical ward for infected sebaceous cyst and newly diagnosed diabetes mellitus. He was incidentally noted to have features of acral overgrowth for fourteen years. He had an occasional headache but did not have any visual symptoms. On review, he has prominent acromegalic features with bilateral temporal hemianopia. His diagnosis of acromegaly was based on markedly elevated IGF-1 and non-suppressible GH after 75g-OGTT.

Pituitary MRI showed giant pituitary macroadenoma 4.1 x 2.5 x 4.1 cm in size, with cavernous sinus invasion and extrasellar extension. Preoperative medical treatment with octreotide-LAR was started considering the invasive features of the macroadenoma and he was scheduled for endoscopic transsphenoidal excision of macroadenoma following multidisciplinary team discussion. Intraoperatively, the tumour was found to have soft and firm areas with components of calcification and bone fragments. Complete removal was not feasible due to adherence of calcified tumour to the optic nerve and arachnoid plane. The patient still requires inpatient monitoring for post-operative CSF leakage at present. It is important to recognise the presence of calcification within a pituitary tumour as its extent may influence the choice of surgical approach. MRI was not able to verify the true extent of calcification due to signal dropout of calcium. As complete resection is technically challenging in calcified large adenomas, medical therapy and/or radiotherapy are usually required to achieve biochemical remission.

Conclusion
Recognising calcification in pituitary adenomas on preoperative imaging is important in decision-making. Total resection can be difficult to achieve in extensive calcification and necessitates non-surgical management to achieve disease control.